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Two-Dimensional Nanomaterials for Drug Delivery in Regenerative Medicine
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
Zahra Mohammadpour, Seyed Morteza Naghib
The integration of bioactive components and graphene-based matrices has been proposed to be promising for wound healing (Mellado et al. 2018; Liu et al. 2017a). Mellado et al. developed a composite aerogel based on GO and poly vinyl alcohol (PVA) into which an extract of grapes rich in proanthocyanidins was incorporated (Mellado et al. 2018). High absorption of blood demonstrated the aerogel’s haemostatic property. The cumulative release of the extract did not exceed 20%, probably due to the strong interaction between the aerogel and the extract in the form of covalent bonding. Tanum et al. investigated the sustained and prolonged delivery of nitric oxide as a therapeutic gas from a solid film (Tanum et al. 2019). A molecular source of NO gas was conjugated to the surface of GO by covalent functionalisation. Due to the multilayer nature of the film, the released NO was physically trapped, which made the diffusion length long. The gas was stabilised by hydrogen bonding. Therefore, the unfavourable burst release of NO was prevented, and the release time of the gas was prolonged. The tortuosity of the path caused by the stacked GO sheets was also responsible for tunable oxygen delivery. Jalani et al. showed that the integration of GO with perfluorocarbon emulsions slowed down the release of oxygen and stabilised the emulsion (Jalani et al. 2017). The perfluorocarbons can absorb large amounts of oxygen and are suitable as alternatives to blood for the oxygen supply of tissues.
Shock and blood transfusion
Published in Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie, Bailey & Love's Short Practice of Surgery, 2018
Professor Sir Norman Williams, Professor P. Ronan O’Connell, Professor Andrew W. McCaskie
Haemoglobin is seen as the obvious candidate for developing an effective blood substitute. Various engineered molecules are under clinical trials, and are based on human, bovine or recombinant technologies. Second-generation perfluorocarbon emulsions are also showing potential in clinical trials.
Nanoemulsion Formulations for Tumor-Targeted Delivery
Published in Mansoor M. Amiji, Nanotechnology for Cancer Therapy, 2006
Sandip B. Tiwari, Mansoor M. Amiji
Perfluorocarbon emulsions are being clinically evaluated as artificial oxygen carriers to reduce allogeneic blood transfusions or to improve tissue oxygenation.13 Perfluorochemicals are chemically inert synthetic molecules that primarily consist of carbon and fluorine atoms and are clear, colorless liquids. They have the ability to physically dissolve significant quantities of many gases, including oxygen and carbon dioxide. Perfluorochemicals are hydrophobic and are not miscible with water. Perfluorochemicals have to be emulsified for intravenous use. To mimic the natural oxygen carrying cells (RBCs), the droplet size of perfluorocarbon emulsions is maintained in sub-micron range (median diameter < 0.2 μm). Egg phospholipid has been used as an emulsifier of choice in these formulations. The examples of the commercial perfluorocarbon emulsions are Oxygent™ (Alliance Pharmaceutical Corporation, San Diego, CA, U.S.A.), Oxyfluor® (Hemagen Inc., St Louis, MO, U.S.A.) and Fluosol-DA (Alpha Therapeutic Corp., Los Angeles, CA, U.S.A.).
Systemic and microvascular comparison of Lactated Ringer’s solution, VIR-HBOC, and alpha-alpha crosslinked haemoglobin-based oxygen carrier in a rat 10% topload model
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2020
Bjorn K. Song, W. Richard Light, Kim D. Vandegriff, Joe Tucker, William H. Nugent
VIR-HBOC has already shown promise in ex vivo organ perfusion studies [17,18] and is further explored here in its first in vivo pre-clinical study. Aims were to determine any vasoconstrictive and hypertensive effects and circulatory half-life in a well-established topload (TL) model that has been employed to evaluate second- and third-generation HBOCs and perfluorocarbon emulsions for over a decade [19–22]. The rat model has been useful because it supports comprehensive physiological and microcirculatory instrumentation for simultaneous monitoring of systemic and localized responses to treatment. The TL approach is more appropriate than hemodilution or haemorrhagic shock (efficacy) models due to the potentially confounding impact of trauma on determining whether VIR-HBOC is vasoactive and hypertensive.
In vitro model to compare the oxygen offloading behaviour of dodecafluoropentane emulsion (DDFPe)
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Meghna S. Jayaraman, Kaitlin Graham, Evan C. Unger
Perfluorocarbons (PFCs) have a long history of being explored as red blood cell substitutes (RBCS) since 1966, when Clark and Gollan demonstrated that a rat immersed in an oxygenated, perfluorocarbon solution could respire normally. The hyperfluorination present in PFCs results in an ideal gas like chemical inertness that allows for lack of metabolism in vivo [5] and additionally allows for the dissolving of gases of similarly low cohesivity such as O2, CO2, N2 and NO [6]. The efficacy of PFC’s as an oxygenation therapeutic, however, is due to its lower affinity for the O2 molecule in comparison to haemoglobin. Under atmospheric PO2, PFCs are much less efficient oxygen-dissolving agents than blood; however, physiologically, the oxygen delivery capability takes priority over the oxygen dissolving capability [7]. The combination of PFCs lower affinity for O2, in concurrence with its higher diffusion rates, allows for more efficient O2 delivery and extraction by the tissues [8]. However, isolated PFCs are not stable enough to be used as an injectable therapeutic. Consequently, recent PFC-based studies have investigated the use of stabilized perfluorocarbon emulsions, which utilize the encapsulation of PFCs in a surfactant monolayer to allow for the prolongation of its intravascular stability and half-life [9].
PFOB sonosensitive microdroplets: determining their interaction radii with focused ultrasound using MR thermometry and a Gaussian convolution kernel computation
Published in International Journal of Hyperthermia, 2022
Ryan Holman, Laura Gui, Orane Lorton, Pauline Guillemin, Stéphane Desgranges, Christiane Contino-Pépin, Rares Salomir
Perfluorocarbon emulsions have gained much interest in recent years for focused ultrasound therapies. The microdroplets have the potential to reduce applied energy and side effects. The potential focused ultrasound applications of these emulsions are relevant to ultrasound guided treatment and magnetic resonance guided treatment, and include: drug delivery, [1–3] lithotripsy, [4] sonothrombolysis, [5] and ablation [6,7]. These pharmaceuticals have not yet entered into clinical trials for ablative therapy and hyperthermia. Further characterization and testing might help translate the technique into a pilot study.